1. Field of the Invention
This invention relates to computer architecture. In particular, the invention relates to multiprocessor systems.
2. Description of Related Art
In a multiprocessor system, several processors are connected to a bus to communicate with each other and with other devices. A processor that has control of the bus is referred to as a master. Examples of a master include central processing unit (CPU), digital signal processor (DSP), and direct memory access (DMA) controller. A device that can only respond to a bus operation (e.g., read, write) initiated by a master is referred to as a slave. Examples of a slave include memory device, serial input/output device, and universal asynchronous receiver and transceiver (UART).
In a typical multiprocessor system, there are several masters and slaves. The masters usually have to compete for the use of the bus. When a master is using the bus, other masters have to wait. The problem is even more severe when several masters want to access several slaves at the same time.
Therefore, there is a need to have a technique to utilize the bus efficiently.